Red Sox trade Kevin Youkilis to White Sox

The Boston Red Sox on Sunday traded Kevin Youkilis, a significant part of their World Series championship five years ago and a Fenway Park favorite for nine years, to the Chicago White Sox for two players, right-handed pitcher Zach Stewart and utility player Brent Lillibridge, according to team sources.

The Red Sox also will pay a large portion of Youkilis' contract.

The transaction comes days after Youkilis, 33, was told he would lose playing time to rookie Will Middlebrooks at third base and in the midst of Youkilis' worst professional season. "Youk" missed three weeks in May because of a lower-back ailment and struggled to find a stroke that once made him a critical part of a formidable Red Sox offense. He is batting .163 since June 2.

He did play – and had two hits – in Sunday's 9-4 win over the Atlanta Braves at Fenway Park. Removed from the game for a pinch-runner, Youkilis, who according to sources had grown unhappy with his diminished role, received loud applause from fans there. During the prolonged ovation, Youkilis came out of the dugout and waved. Before then, the Youkilis situation had become untenable for both the player and management.

In a season of transition for the Red Sox that has been trying for everyone, Youkilis had been among those most affected.

In mid-April, manager Bobby Valentine told reporters Youkilis appeared detached.

"I don't think he's as physically or emotionally into the game as he has been in the past for some reason," Valentine said.

Valentine apologized the following day, but the Red Sox had their first public conflict and clubhouse discord. Veteran Dustin Pedroia came to Youkilis' defense.

[More Tim Brown: It's time for the Boston Red Sox to grow up]

"I don't know what Bobby's trying to do, but that's not the way we do things here," he said. "Maybe that stuff works in Japan."

The Red Sox were on their way to a 4-10 start, rattling Back Bay nerves and summoning memories of a September collapse that cost the club a playoff spot, then popular manager Terry Francona his job. The club has played better since, and by Sunday afternoon were 1½ games out in the wild-card race.

Once Youkilis was healthy, Middlebrooks had become one of the Red Sox's more productive hitters, creating a lineup quandary for Valentine. So, Youkilis played some third and some first, in the latter games forcing first baseman Adrian Gonzalez into right field.

[Related: Cody Ross homers twice in Boston's 9-4 win over Atlanta]

Red Sox general manager Ben Cherington shopped Youkilis for weeks, but generally found the market lukewarm. Many scouts questioned whether Youkilis could recapture the swing that once made him an All-Star and MVP candidate. He'd also won a Gold Glove at first base in 2007. There also was concern Youkilis could not withstand regular playing time at third base, given his recent history with injuries. Youkilis' salary – he's due $12 million this season, or a little more than $7 million for the rest of the season – further complicated negotiations. The Red Sox are expected to include $5.5 million in the deal with the White Sox.

The Los Angeles Dodgers, Cleveland Indians and Atlanta Braves were among the clubs believed to have sincere interest in acquiring Youkilis, who was batting .233 with a .315 on-base percentage, both career lows.

An unexpected contender in the AL Central, the White Sox have gotten almost no production from third base. Starter Brent Morel was lost to a back injury. Orlando Hudson was signed a month ago and has batted .167 since. In all, White Sox third basemen have one home run and 18 RBIs, both the least in the American League.

Stewart, 25, has a 5.92 ERA in 31 career big-league appearances, 18 of them – including one start – this season. He was traded to the White Sox from Toronto at the trading deadline last year in the deal involving Edwin Jackson and Mark Teahen. He has been used as both a starter and reliever.

In five major-league seasons, Lillibridge, 28, has played every infield and outfield position. The career .215 hitter batted .175 in 48 games for the White Sox this season.

Other popular content on the Yahoo! network:
Fantasy baseball video: Rookies on rise in stock watch
Dan Wetzel: Jerry Sandusky is guilty and his sex abuse victims are heroes for testifying
Who could become the biggest bust of this year's NBA draft?
Y! Education: Six great careers for members of the 'nerd herd'